Tube for ventricular assist device

Abstract

Apparatus and methods are described including a ventricular assist device that includes a tube configured to traverse a subject's aortic valve. The tube defines a generally-cylindrical central portion, and a proximal conical portion that narrows from a proximal end of the central portion to a proximal end of the tube. The tube defines one or more blood inlet openings in a vicinity of a distal end of the tube, and one or more blood outlet openings that extend axially from the central portion of the tube at least partially into the proximal conical portion of the tube. A blood pump pumps blood into the tube from the subject's left ventricle through the one or more blood inlet openings, and from the tube into the aorta through the one or more blood outlet openings. Other applications are also described.

The invention claimed is: 
     
       1. An apparatus comprising:
 a ventricular assist device comprising:
 a tube configured to traverse an aortic valve of a subject, such that a proximal end of the tube is disposed within an aorta of the subject and a distal end of the tube is disposed within a left ventricle of the subject,
 the tube defining a cylindrical central portion, and a proximal conical portion that narrows continuously from a proximal end of the central portion to a proximal end of the tube, and 
 the tube defining one or more blood inlet openings in a vicinity of a distal end of the tube, and one or more blood outlet openings that extend axially from the central portion of the tube at least partially into the proximal conical portion of the tube; 
 
 an impeller configured to pump blood into the tube from the left ventricle through the one or more blood inlet openings, and out of the tube into the aorta through the one or more blood outlet openings, the entire impeller being configured to be disposed within the distal end of the tube during operation of the impeller. 
 
 
     
     
       2. The apparatus according to  claim 1 , wherein at least a portion of the tube is collapsible, such that:
 in response to pressure outside of the portion of the tube exceeding pressure inside the collapsible portion of the tube, the collapsible portion of the tube collapses inwardly, and 
 during operation of the impeller, pressure of the blood flow through the tube maintains the collapsible portion of the tube in an open state. 
 
     
     
       3. The apparatus according to  claim 1 , wherein the tube further defines a distal conical portion that narrows from a distal end of the central portion to a distal end of the tube. 
     
     
       4. The apparatus according to  claim 1 , wherein the one or more blood inlet openings are lateral with respect to a longitudinal axis of the tube. 
     
     
       5. The apparatus according to  claim 4 , wherein the tube defines between two and four lateral blood inlet openings. 
     
     
       6. The apparatus according to  claim 1 , wherein the tube defines between two and eight blood outlet openings that extend axially from the central portion of the tube at least partially into the proximal conical portion of the tube. 
     
     
       7. The apparatus according to  claim 6 , wherein the tube defines between two and four blood outlet openings that extend axially from the central portion of the tube at least partially into the proximal conical portion of the tube. 
     
     
       8. The apparatus according to  claim 1 , wherein the one or more blood inlet opening defines a single axially-facing blood inlet opening at a distal end of the cylindrical portion of the tube. 
     
     
       9. The apparatus according to  claim 1 , wherein the ventricular assist device further comprises a frame disposed around the impeller, wherein a portion of the tube that defines the blood inlet opening is disposed around the frame. 
     
     
       10. The apparatus according to  claim 1 , wherein the ventricular assist device further comprises a distal tip portion disposed distally with respect to the impeller, and wherein, during operation of the ventricular assist device, a distance between the impeller and the distal tip portion is within a distal-most 50 percent of the tube. 
     
     
       11. The apparatus according to  claim 10 , wherein the ventricular assist device further comprises a distal tip portion disposed distally with respect to the impeller, wherein, during operation of the ventricular assist device, a distance between the impeller and the distal tip portion is within a distal-most 30 percent of the tube. 
     
     
       12. The apparatus according to  claim 1 , wherein at its proximal end, the central portion of the tube has a diameter of between 5 and 7 mm, and at its distal end, the central portion of the tube has a diameter of between 8 and 12 mm. 
     
     
       13. The apparatus according to  claim 1 , wherein the one or more blood outlet openings extend axially from the proximal end of the central portion of the tube.